My Yamaha R3 receiver loses it's stored AM/FM channels when power switch is off for
more than a few minutes.
The power switch directly switches all mains power in the unit, i.e., there is no
standby supply to any circuits.
I cannot see any internal battery.
I therefore think the problem is a faulty memory device LC7030 or a faulty
capacitor.

Do they use caps (electro) for memory retention?

The user manual states that the Receiver may lose it's stored channels when
*unplugged* for a long time. As far as I can tell being switched off is equivalent
to being unplugged.

I would like to understand the circuit around this LC7030 device which appears to be
where the channels get stored. Does anyone have a R3 circuit diagram or datasheet
for Sanyo LC7030.

Thanks for any advice.

The backup capacitor is bad. It looks like a "button" and is near the main
micro IC on the main board, if memory serves. Yamaha still stocks a
replacement.

This model takes rather more effort to get into than many receivers. The
average DIY type or non-tech would likely have a problem with this one.


Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Rob" wrote in message
...
My Yamaha R3 receiver loses it's stored AM/FM channels when power switch
is off for
more than a few minutes.
The power switch directly switches all mains power in the unit, i.e.,
there is no
standby supply to any circuits.
I cannot see any internal battery.
I therefore think the problem is a faulty memory device LC7030 or a faulty
capacitor.

Do they use caps (electro) for memory retention?

The user manual states that the Receiver may lose it's stored channels
when
*unplugged* for a long time. As far as I can tell being switched off is
equivalent
to being unplugged.

I would like to understand the circuit around this LC7030 device which
appears to be
where the channels get stored. Does anyone have a R3 circuit diagram or
datasheet
for Sanyo LC7030.

Thanks for any advice.

I've now replaced the backup capacitor (super cap) and the unit is working a treat.
Thanks for your advice Mark,
Rob

"Mark D. Zacharias" wrote:

The backup capacitor is bad. It looks like a "button" and is near the main
micro IC on the main board, if memory serves. Yamaha still stocks a
replacement.

This model takes rather more effort to get into than many receivers. The
average DIY type or non-tech would likely have a problem with this one.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.

"Rob" wrote in message
...
My Yamaha R3 receiver loses it's stored AM/FM channels when power switch
is off for
more than a few minutes.
The power switch directly switches all mains power in the unit, i.e.,
there is no
standby supply to any circuits.
I cannot see any internal battery.
I therefore think the problem is a faulty memory device LC7030 or a faulty
capacitor.

Do they use caps (electro) for memory retention?

The user manual states that the Receiver may lose it's stored channels
when
*unplugged* for a long time. As far as I can tell being switched off is
equivalent
to being unplugged.

I would like to understand the circuit around this LC7030 device which
appears to be
where the channels get stored. Does anyone have a R3 circuit diagram or
datasheet
for Sanyo LC7030.

Thanks for any advice.

Glad that worked out for you.

mz

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Rob Haughey" wrote in message
...
I've now replaced the backup capacitor (super cap) and the unit is working
a treat.
Thanks for your advice Mark,
Rob

"Mark D. Zacharias" wrote:

The backup capacitor is bad. It looks like a "button" and is near the
main
micro IC on the main board, if memory serves. Yamaha still stocks a
replacement.

This model takes rather more effort to get into than many receivers.
The
average DIY type or non-tech would likely have a problem with this one.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.

"Rob" wrote in message
...
My Yamaha R3 receiver loses it's stored AM/FM channels when power
switch
is off for
more than a few minutes.
The power switch directly switches all mains power in the unit, i.e.,
there is no
standby supply to any circuits.
I cannot see any internal battery.
I therefore think the problem is a faulty memory device LC7030 or a
faulty
capacitor.

Do they use caps (electro) for memory retention?

The user manual states that the Receiver may lose it's stored channels
when
*unplugged* for a long time. As far as I can tell being switched off
is
equivalent
to being unplugged.

I would like to understand the circuit around this LC7030 device which
appears to be
where the channels get stored. Does anyone have a R3 circuit diagram
or
datasheet
for Sanyo LC7030.

Thanks for any advice.